The present invention relates to a semiconductor device and a manufacturing technology thereof, in particular, to a technology that is effective when applied to a semiconductor device in which the thickness is reduced by grinding the back side of the semiconductor device.
As a technology for reducing the thickness of a semiconductor device, there is such a technology that, after forming an integrated circuit over the principal surface of a semiconductor wafer, the back side is ground.
For example, Japanese Patent Laid-Open No. 2004-253678 (Patent Document 1) describes the grinding of the back surface of a semiconductor wafer and, after that, the formation of a bank pattern made of polyimide resin for a part of a scribe line to be cut off. The Patent Document 1 describes that the infiltration of a grinding fluid into a gap between a surface protective tape and the scribe line can be prevented at the grinding of the back surface of the semiconductor wafer.
Moreover, for example, Japanese Patent Laid-Open No. 1993-315304 (Patent Document 2) describes the formation of a polyimide film uniformly for the peripheral part of a wafer. The Patent Document 2 describes that the adhesiveness between the wafer and the protective sheet is improved to make it possible to prevent the penetration of water, acid etc. to the wafer surface.
Moreover, for example, Japanese Patent Laid-Open No. 2001-274129 (Patent Document 3) describes the formation of a bank made of polyimide resin near intersections of scribe lines running in a lattice shape. The Patent Document 3 describes that it can prevent the penetration of grinding waste through a concave part with no polyimide film at the outer periphery of the wafer in the process of grinding the back surface.